1. Field of the Invention
The invention is related to the field of phlebology, mainly involved in therapeutic treatments of the venous system. More particularly, the invention is related to a non-invasive method including the use of a light source in combination with chemical therapy for treatment of venous disorders, such as varicose veins and telangiectasias.
2. Information Disclosure Statement
Frequently, a considerable number of men and women suffer from venous system pathologies, including varicose and spider veins. Varicose veins alone affect up to 60 percent of older people.
Varicose veins refer to blood vessels that have become enlarged and twisted and have progressively lost their wall elasticity. Owing to the widening of the blood vessels, vein valves cannot be completely closed and veins lose their ability to carry blood back to the heart. This leads to an accumulation of blood inside the vessels, enlarging and twisting the veins even more. Furthermore, varicose veins usually have a blue or purple color and may protrude above the surface of the skin, being responsible for their characteristically unattractive appearance. They are commonly formed in the superficial veins of the legs, which are subject to high pressure when standing. Other types of varicose veins include reticular veins, phlebectasias and telangiectasias These vein disorders generally consists of thin, dark-colored, small dilated blood vessels that lie close to the surface of the skin. The dilated small veins often have a web or sunburst pattern, but may also appear as random line segments. They can develop anywhere on the body but most commonly on the lower limbs, typically on the upper thigh, below the knee joint, and around the ankles, and also on the face around the nose, cheeks, and chin and on the back of the hands.
There are a number of symptoms associated with varicose and spider veins, such as aching, itching, burning, swelling, feeling of heaviness in the legs, throbbing and muscle cramping. Even though some patients are asymptomatic they treat varicose or spider veins for cosmetic reasons. Nevertheless, in some cases varicose veins have more serious complications including thrombophlebitis, dermatitis, hemorrhage, inflammation and ulcers. Usually, with varicose veins, phlebitis may occur spontaneously or as a result of an injury. Moreover, scratching when it itches may cause bleeding or development of a painful ulcer that does not heal.
There are a number of treatments available intended to eradicate these kinds of vascular pathologies. Some of the treatments relieve the symptoms but do not prevent new varicose veins from forming. Such treatments may include elevating the legs by lying down or using a footstool when sitting, use of elastic stockings and exercise.
Surgical treatments are an alternative available treatment. Some surgical therapies consist of the removal of the vein by: 1) stab avulsion phlebectomy, where the vein is removed by making a series of incisions, inserting a hook, gripping and pulling out the affected vein; 2) vein stripping, a procedure that involves making two incisions and tearing out the vein axis using a wire; 3) catheter-assisted procedures, where a catheter is inserted into the vein to be treated. Its tip is heated, and then, as the catheter is pulled out, the heat causes vein ablation.
Use of surgical therapies has several disadvantages compared to other approaches. One of them is the need for general, local or peridural anesthesia. Furthermore, these procedures may damage collateral branches of the vein which may consequently bleed, giving rise to hematomas, or may lead to other complications such as blood loss, pain, infection, nerve injury or swelling. Moreover, because of the damage done to the treated area, patients may suffer pain and discomfort during hours or days after surgery. Fortunately, there is another surgical option for the treatment of blood vessels namely, laser surgery, which has been improved due to new diode laser equipments. Endovascular laser surgery consists of applying laser radiation and providing thermal (or photo-thermal) energy to the vein wall with the aid of an optical fiber. While the optical fiber is withdrawn the vein closes and the blood vessel irreversible evolves into fibrotic tissue.
However, surgery is not the only option. There are some non-surgical treatments like sclerotherapy, that have been used for treating varicose veins for almost 150 years. In US Patent Application US 2006/0106350A1 by Spitz titled “Apparatus and Methods for Treating Undesired Veins”, methods and apparatus for treating undesired veins are disclosed. A typical treatment session consists of introducing the sclerosing agent inside the vein to be treated. Once the sclerosing agent is inside the vein, it begins to irritate the internal lining of the blood vessel, causing inflammation and, eventually clotting and scaring. Depending on the concentration and strength of the sclerosing solution, between 30 to 40 syringes may be needed. One of the main disadvantages of sclerotherapy treatments is the pain associated with the use of syringes and the resulting discomfort of patients.
Nowadays, there are some treatments that include both sclerotherapy and laser treatments in order to improve therapies available for treating vascular pathologies. In an attempt to improve the combination of sclerotherapy and laser light in the treatment of superficial venous pathologies Navarro et al. disclosed a treatment for spider veins in US Patent Application US 2007/0282248A1 and International Patent Application WO 2007/131199A2 titled “Cosmetic Method and Kit for Treatment of Spider Veins and Other Superficial Venous Pathology”; and varicose veins in US Patent Application US 2007/0260229A1 titled “Method and Kit for Treatment of Varicose Veins and Other Superficial Venous Pathology”. The procedure consists of piercing the vein to be treated percutaneously, and then, following the sclerotherapy treatment or after a dwell time, laser light is directed to the area of the patient's skin affected by the piercing step. Multiple non-hypertonic sclerosing agents and/or chromophores injections may be used. Despite the combination of treatments one of its main disadvantages is that the sclerosing agents used in this invention may cause an allergic reaction, thus limiting their use. Moreover, to obtain an efficient therapy the treatment area needs to exhibit ecchymosis. This leads to unpleasant patient discomfort due to swelling and pain associated with bruises in general. Moreover, after directing light, not only the target vein is degraded but also the whole area with extravasated blood, requiring wound dressings to treat the area after the procedure is completed.
Instead of using a sclerosing agent, a device for removing visible veins on the leg with indocyanine green as a chromophore is disclosed by Abels et al. in U.S. Pat. No. 6,491,715 titled “Device for Treating Growing, Dilated or Malformed Blood Vessels and Method for Treating Biological Material”. The device has a control unit which controls the power of the laser depending on the concentration of chromophore in the patient. One of the main disadvantages of this treatment is that the chromophore needs to be uniformly distributed in the whole vascular system prior to laser treatment, not just in the area that needs to be treated. Moreover, commercial indocyanine green may cause an allergic reaction, thus limiting its extensive use. In addition, the treatment requires the delivery of laser radiation pulses of powers as high as 100 to 800 Watts; thus not only malformed vessels are heated but also the tissue surrounding the treated vessel may be damaged. Furthermore the device needs two lasers, one for therapy and the other one for determining chromophore concentration, becoming an expensive and voluminous device not always easy to place in an operating theatre.
Another attempt to eliminate varicose veins using laser radiation and a photodynamic sclerosis composition is disclosed in International Patent Application WO 2007/133525 A2 by Castro et al., having the same assignee as the present invention, titled “Photodynamic Foam Composition and Sclerosis Treatment”. The photodynamic sclerosis composition is a foam that comprises a photosensitizer, a detergent and a glucose solution. The method consists of introducing the photodynamic sclerosis composition into the vein to be treated and after a sufficient time, applying radiation of appropriate wavelength absorbed by the composition, to activate the photosensitizer. According to the patent, the invention allows for full control of the drug concentration inside the vein, improved time of contact between the sclerosing agent and the endothelium, increased intimate destruction and quicker transformation of the varicose veins into a fibrotic cord and its posterior elimination, by phagocytosis. Nevertheless, for an effective treatment the photodynamic sclerosis composition comprises a detergent solution known as polydodecanol, a sclerosing agent, which may often induce dark cutaneous pigmentations, more frequently for small vessels, such as telangiectasia.
Therefore there is a need for an effective treatment capable of overcoming the main disadvantages of other therapies currently available for treating venous pathologies, such as varicose and spider veins. Moreover, there is a need for an ambulatory painless treatment, able to provide fast recovery and improved therapeutic results, without generating serious potential side effects, not causing allergic reactions and with no anesthesia requirements. The present invention addresses this need.